H+/O+ escape rate ratio in Venus’ magnetotail and its dependence on the solar cycle
Astract:
An open issue for Venus atmospheric evolution is to answer how the presumably large water content was lost. We use eight years of data collected by the ion mass analyser instrument onboard the Venus Express mission. We investigate the escape of hydrogen H+ and oxygen O+ ions, the components of water, from Venus atmosphere to space. If water is escaping from Venus entirely as ions the hydrogen to oxygen ion ratio should be close to 2. We find that for the solar minimum period the ratio of H+/O+ ion escape is 2.6, while for solar maximum, when the sun is at its most active, the escape is close to 1-to-1. Thus, in the current state Venus is on average losing water from its atmosphere. However, in the early history of the solar system, when the Sun was in an even more active state, the escape ratio was probably below the water ratio. In this presentation I will discuss more on the results and the potential effects on the Venus atmospheric evolution.
Created 2017-10-05 08:51:25 by Mats Holmström Last changed 2018-08-27 09:49:42 by Mats Holmström
